Day25 - Functional Endpoints

15th鐵人賽

James

2023-10-11 06:39:30

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Day25 - Functional Endpoints

前言

Spring MVC 5.2起提供一種輕量級functional programing model的方式來處理Web請求，就讓我們來看看有別於Controller+RequestMapping的方式吧

專案建立

Functional Endpoints

Web請求處理方式

@Controller + @RequestMapping：耦合式(路由與業務耦合)

@RestController
public class HelloController {

    @GetMapping("/hello")
    public String hello(){
        return "Hello";
    }
}

Functional Endpoints：分離式(路由與業務分離)

Core

RouterFunction：定義路由訊息、發什麼請求、由誰處理
RequestPredicate：定義請求：請求方式、請求參數
ServerRequest：封裝請求完整參數
ServerResponse：封裝回應完整參數

demo code

Bean

@Data
@AllArgsConstructor
public class Person {
    private String name;
    private String id;
}

Repository

@Slf4j
@Repository
public class PersonRepository {

    public void create(Person person){
        log.info("===Repository=== create person："+person);
    }
    public Person findById(String id){
        log.info("===Repository=== getPersonById："+id);
        return new Person("james","3");
    }
    public List<Person> findAll(){
        log.info("===Repository=== findAll");

        List<Person> list = new ArrayList<>();
        Person p1 = new Person("p1","1");
        Person p2 = new Person("p2","2");
        list.add(p1);
        list.add(p2);
        return list;
    }
    public void update(Person person){
        log.info("===Repository=== update；"+ person);
    }
    public void delete(String id){
        log.info("===Repository=== delete；"+id);
    }

}

Handler

@Component
public class PersonHandler {
//    @Autowired
    private PersonRepository personRepository;

    public PersonHandler(PersonRepository personRepository) {
        this.personRepository = personRepository;
    }


    public ServerResponse getPersonById(ServerRequest request) {
        Person person = personRepository.findById(request.pathVariable("id"));
        return ServerResponse.ok().body(person);
    }
    public ServerResponse updatePerson(ServerRequest request) throws ServletException, IOException {
        Person person = request.body(Person.class);
        personRepository.update(person);
        return ServerResponse.ok().build();
    }

    public ServerResponse listPeople(ServerRequest request) {
        List<Person> list = personRepository.findAll();
        return ServerResponse.ok().body(list);
    }

    public ServerResponse createPerson(ServerRequest request) throws ServletException, IOException {
        //提取请求体
        Person body = request.body(Person.class);
        personRepository.create(body);
        return ServerResponse.ok().build();
    }

    public ServerResponse deletePerson(ServerRequest request) throws ServletException, IOException {
        personRepository.delete(request.pathVariable("id"));
        return ServerResponse.ok().build();
    }

}

PersonRouterConfig，可以比較一下先前使用Controller + RequestMapping的方式

@Configuration
public class PersonRouterConfig {

    @Bean
    public RouterFunction<ServerResponse> routes(PersonHandler handler) {
        return RouterFunctions.route(GET("/api/person"), handler::listPeople)
                .andRoute(POST("/api/person"), handler::createPerson)
                .andRoute(GET("/api/person/{id}"), handler::getPersonById)
                .andRoute(PUT("/api/person/{id}"), handler::updatePerson)
                .andRoute(DELETE("/api/person/{id}"), handler::deletePerson);
    }
}